Hello info@tornat.ca,
I searched our online knowledgebase, and found this article for lines or streaks with using the ADF that may help you.
I am using the autofeed scanning on both side of the papers.
Odd pages came out clear but even pages came out with a wide black stripe along the pages.
It also happens when I use the auto feed for copying two sides.
The odd pages came out with a wide (one inch) along the page.